Something that I've done with some success is simply applying a soaking wet paper towel to the poop to really soften it. With the car in the shade, I just gently lay (DON'T RUB) it right on the spot. After, say, five minutes, I gently lift the towel (DON'T RUB). The poop should be completely soft now. Then I apply a spray of water to wash away the remnants. If there's still some caked on, repeat the first step. Once all the crap is washed away, I'll give a spritz of quick detailer, buff it, and call it good. Or you can clay bar, polish and then apply your favorite wax, if more time is available.
The secret is get it off quick and don't rub any of the abrasives into the paint.